A semiconductor device is manufactured by forming a semiconductor element such as a MISFET in a semiconductor substrate, forming a multilayer wiring structure having a plurality of wiring layers over the semiconductor substrate, and forming a passivation film in the uppermost layer thereof. The semiconductor device has a pad for wire bonding. The pad is exposed from an opening provided in the passivation film. Examples of a wire coupled to the pad include a gold wire and a copper wire.
Japanese Unexamined Patent Publication No. 2013-4781 (Patent Document 1) describes a technique related to a semiconductor device which can be electrically coupled using a bonding wire containing copper as a main component.
Japanese Unexamined Patent Publication No. 2002-76051 (Patent Document 2) describes a technique related to a bonding pad structure in a semiconductor device.
Japanese Unexamined Patent Publication No. Hei 9(1997)-74097 (Patent Document 3) describes a technique related to a method of forming a barrier metal.